We have a Virtualmin server configured with Maildirs under each user's home directory. Under each Maildir exists the "special" folders .Sent, .Trash, .Drafts and .Spam.
Usermin's Read Mail function, when configured for Maildir, does not appear to correctly auto-detect any of the special folders. There are config options to manually override Sent and Drafts, but none for Trash. As a result, deleted messages from Read Mail get put into ~/Maildir/.trash. If that folder doesn't exist, it gets created, effectively causing our users to have both .Trash and .trash. Mail deleted via IMAP goes to Trash, and mail deleted via Usermin goes to trash.
Temporarily I've configured Read Mail to discard messages immediately when deleted to avoid the second folder creation.
Could you either fix the autodetection of folders, and/or add an override option for the Trash folder?